So how is my service using this servlet?As in what's the use of a servlet in a REST Service?Is the service just a framework that uses the servlet's built in HTTP methods?

网友答案:

CXFServlet is one of the transport Apache CXF uses in order to publish rest services. In other words CXF uses under the hood when publishing a Rest services JAXRS annotated (@Path) a simple Java Servlet.
So the final URL where your rest services will be deployed is a concatenation between CXFServlet mapping and your rest services path.

There are other kind of transport. See http://cxf.apache.org/docs/transports.html just to understand that they are more options.